1. Field of the Invention
The present invention relates to a semiconductor device and, more specifically, relates to a semiconductor device including a high electron mobility transistor (HEMT).
2. Description of the Related Art
High electron mobility transistors (HEMTs) including gallium nitride (GaN) compound semiconductors have been conventionally known. The HEMTs have low resistance and high breakdown voltage and are used in power applications, for example.
US 2006/0175627A1 discloses a power supply system (a synchronous rectification circuit) capable of increasing the power conversion efficiency of a non-isolated DC/DC converter and therefore realizing a high power supply efficiency. In this conventional power supply system, a series circuit of a high side switch and a low side switch is provided between a DC power terminal and a ground terminal. The high side switch is composed of an HEMT having a lateral structure, and the low side switch is composed of a power MOSFET having a vertical structure. The switch elements of the series circuit are controlled by a driver IC to be alternately turned on and off. The power supply system then converts input power to a predetermined DC power. In the power supply system, use of an HEMT as the high side switch can reduce the switching loss and conduction loss.